Grinding machines



Oct. 23, 1962 1. LUBBOCK GRINDING MACHINES Filed Feb. 3, 1960 INVENTOR mc A, Vii/5006 BY ll ziiec u F, C 241160 ATTORNEY Unite its This invention relates to grinding machines for sharpening knives or similar edge tools all of which are herein referred to as knives.

According to the invention there is provided a grinding machine which comprises two grinding wheels spaced axially from each other on a common drive shaft and, arranged between the adjacent faces of the grinding wheels and spaced equally from them, a jig adapted to support a knife in a sharpening position.

In a preferred embodiment of this invention illustrated in the accompanying drawing, a grinding machine comprises a base 1 on which is a housing 2 for driving motor 3 which is preferably an electric motor. A drive shaft 4 projects horizontally from the motor 3 and carries two grinding wheels 5 and 6 which are spaced axially from each other. Wheel guards 7 and 8 project the wheels 5 and 6.

A jig 9 for supporting a knife to be sharpened is arranged between the adjacent faces of the wheels 5 and 6 and is spaced equally from them. This jig is mounted on a support frame 10 including a slide vertically movable in a slot in a mounting bracket 11 fixed to the base 1 so that the position of the jig 9 is vertically adjustable. The jig is held in its desired vertical position with respect to the axis of the shaft 4 by tightening a grub screw 12. The jig 9 is of truncated triangular cross section, the inclination of the sides of the jig being such that projections of the planes containing these faces intersect in a plane midway between the grinding wheels and is such that the inclined faces support the knife in a sharpening position, the faces being of suflicient length satisfactorily to guide and support the knife. The faces may be plane faces or they may be convex over all or part of their length to permit the knife to be turned out of the transverse plane bisecting the two wheel faces so as to permit grinding of a narrow tip at its end of the knife.

ates I:

3,059,382 Patented Oct. 23, 1962 ice The guards 7 and 8 are spaced from each other to define a slot through which the knife can be entered to the jig 9. Guide strips 13 and 14 of angular cross section co-operate with the inclined faces of the jig to define narrow slots for guiding the knife so as to locate the knife at the correct angle with respect to the wheel faces. These guide strips are secured in position by screws 15 and may be packed up with packing strips 16 when the jig 9 is raised from its lowermost position. The free end of the shaft 4 can, if desired, project beyond the guard 8 (as shown in broken lines in the drawing) and can carry a polishing mop 17 or other tool.

By vertically adjusting the position of the jig, it is possible to utilise different zones of the grinding wheel faces when wear occurs in any one zone after long use.

What I claim is:

A grinding machine for knives and other edge tools comprising a driving motor, a drive shaft driven by said motor, two grinding wheels spaced axially from each other on said shaft, two axially shiftable wheel guards arranged to shield said grinding wheels and with a varying space between them through which a tool can be passed to the space between said wheels, a vertically adjustable jig arranged centrally between said grinding wheels for locating a tool in a sharpening position with respect to a working face on the upper portion of either one of said grinding wheels, and guide strips depending from the wheel guards into the space between said guards and said jig for cooperating with said jig to locate said tool so that it can only be presented edge first to a working face on either one of said wheels.

References Cited in the file of this patent UNITED STATES PATENTS 813,167 Olmsted Feb. 20, 906 2,124,593 Schaefer July 26, 1938 2,799,125 Dicke July 16, 957 2,841,926 Lebus July 8, 1958 FOREIGN PATENTS 76,346 Netherlands Oct. 16, 1954 

